No abstract

In recent years, LED (light-emitting diode) has been the subject of research within the field of plant growth and development. However, there has been little discussion about using LED in vitro cultures of Panax vietnamensis, one of the important medicinal plants belonging to the Panax genus. This study examines the influence of various LED lamps on callus growth and plant formation of P. vietnamensis. Results show significant differences in growth and development, as various light conditions were suitable for different stages. Callus of 70 mg in fresh weight cultured under yellow LEDs resulted in growth of 1197 mg in fresh weight and 91.7 mg of dry weight, within a period of three months. The most effective plant formation was obtained when embryogenic calli were cultured under the combination of 60% red LED and 40% blue LED with an average of 11.21 plantlets per explant; the shoot clump fresh weight and dry weight were of 1147 and 127 mg, respectively, and the average plant height was 3.1 cm. It was also shown that this light condition was the most efficient for P. vietnamensis in vitro plant growth and development. This study provided additional evidence regarding the influence of different LEDs on ginsenoside production applying high-performance liquid chromatography (HPLC) analysis with photo-diode array (PDA) detection at ultraviolet (UV) wavelength 203 nm. The highest MR2 content was recorded when plants maintained under 20% red LED combined with 80% blue LED. However, the highest Rg1 and Rb1 content was found under fluorescent light. The results presented might provide new strategies using LEDs for adequate micropropagation protocols of P. vietnamensis.

No abstract

No abstract

No abstract

No abstract

Silver nanoparticles (SNPs) are one of metallic nanoparticles widely applied in many fields. Research of SNPs application in plant tissue culture has been gaining attention in recent years. Moreover, novel plant tissue culture systems have been researched and developed for improving SNPs uptake capability in medium. In this study, we investigated effects of SNPs on Chrysanthemum morifolium ramat. cv. "JIMBA" growth and its ability in 3 culture systems: in vitro solid medium system, in vitro liquid medium system and microponic (combined of micropropagation and hydroponic). The 3 cm Chrysanthemum shoots and silver nanoparticles of diameter smaller than 20 nm were used in the experiments. After 4 weeks, the results showed that the SNPs concentration was suitable for growth of Chrysanthemum in vitro solid medium system, in vitro liquid medium system and microponic was 1.5, 1.5 and 5 ppm, respectively. Microponic system not only improved plant growth but also reduced the succulent phenomenon. SNP uptake was likely dependent on concentrations and culture systems. At low concentrations (1, 5, and 10 ppm), SNPs were completely absorbed after 4 weeks of culture in all systems, but not at high concentrations (20 ppm). The amount of absorbed silver nanoparticles was directly proportional to the culture period and inversely proportional to the concentration of SNPs supplemented to the medium. In all of our investigated systems, the hydroponic system showed the highest capability of SNPs absorption.

The minimum miscibility pressure (MMP) CO2 injection performs in enhanced oil recovery (EOR) method to increase sweeping efficiency and reduce oil/CO2 interfacial tension (IFT) also advantageous to the environmental in term of gas emissions for carbon capturing. There are several methods to achieve reliable value of MMP such as slim tube test, raising bubble apparatus, vanishing IFT, swelling test, and visual observation. However, these methods have certain limitations, which leads to the development of new techniques for a wide range of applications. In this paper, a rapid method that integrated IFT test with visual observation was investigated. Based on the test, the pressure is plotted against the IFT to predict the MMP for temperature 60 °C and 66 °C. In the meantime, visual observation during the test is also conducted to identify the occurrence of miscibility. The combination of both methods may provide much faster MMP prediction because the test consumes a small amount of hydrocarbon samples. The outcomes of this research clearly suggest that the MMP values resulted from IFT test and visual observation considerably agree with each other.